The present invention generally relates to air conditioning apparatus, and more particularly relates to housing or cabinetry structures in which the operating components of various types of air conditioning equipment, such as furnaces, air handlers and heat pumps, are disposed for air flow therethrough.
According to currently practiced assembly methods, the operating components of the above-mentioned and other types of air conditioning equipment are typically housed within a rectangularly cross-sectioned cabinet formed from a single layer outer sheet metal jacket having a layer of fibrous insulating material adhered to its interior side surface. Air to be heated and/or cooled is flowed through this interiorly insulated cabinet structure, and across heat exchange apparatus disposed therein, on its way to the conditioned space served by the air conditioning equipment.
While this interiorly insulated cabinet construction is widely accepted and utilized in the modern day heating, ventilation and air conditioning industry, it is subject to various well known problems, limitations and disadvantages. For example, a considerable amount of time and expense is typically involved in cutting the fibrous insulating material (usually in sheet form) to size and adhesively adhering it to the interior side surface of the outer metal jacket portion of the cabinet. Additionally, the inner side surface of the installed fibrous insulation is directly exposed to the air flow internally traversing the cabinet. Bits and pieces of the insulation are thus susceptible to being dislodged and undesirably entrained in the air flow. The exposed placement of the fibrous insulation on the interior surface of the cabinet also increases the resistance to air flow through the cabinet, thereby correspondingly increasing the air-moving power requirement for the furnace. Further, the cabinet wall structure (particularly in larger cabinet sizes) tends to be undesirably flexible and often must be braced in some manner, thereby further adding to the overall fabrication cost associated with the air conditioning equipment.
As an alternative to this single wall cabinet construction, various double-walled cabinet structures have been previously proposed, as exemplified in U.S. Pat. No. 1,195,845 to Neal; U.S. Pat. No. 1,768,584 to Eaglesfield; U.S. Pat. No. 2,324,710 to Livar; and U.S. Pat. No. 2,527,226 to Levine. Each of these patents illustrates and describes a furnace housing having an outer wall structure defined by spaced apart inner and outer metal layers forming therebetween an insulating air space, with the interior side surface of the housing being devoid of insulating material. Accordingly, air flowing through the housing does so along a smooth metal surface, thereby eliminating the potential for entraining fibrous insulation material into the air flow.
While the absence of interior side surface insulation material exposed to air flow through these previously proposed furnace housing structures potentially provides them with a significant operating advantage over their interiorly insulated single wall counterparts, they have significant offsetting disadvantages that have rendered them generally unsuitable for modern day furnace construction. Specifically, each of the four depicted furnace housings is formed from separate double-walled panel sections which must be operatively intersecured using specially designed clip structures and/or fastening members.
For example, the cylindrical furnace housing depicted in U.S. Pat. No. 1, 195, 845 to Neal is formed from six separate wall sections provided along opposite edges thereof with clip structures which must be secured to adjacent clip structures on other wall sections with a multiplicity of threaded fasteners. Likewise, the rectangular furnace housing shown in U.S. Pat. No. 2,324,710 to Livar is formed from four separate double-walled panel structures joined at their adjacent side edges by interlockable clip structures.
Another problem associated with double-walled cabinet structures of conventional construction is the relative complexity of each of their separate double-walled panel sections. For example, each of the four separate housing wall sections shown in the Livar patent comprises inner and outer metal panels to which a series of metal clip members and spacing members must be individually welded before the housing can be assembled. This structural complexity associated with the individual double-walled panel structures, coupled with the complexity and time associated with intersecuring them to form the overall cabinet structure, has heretofore rendered the use of double-walled cabinet structures in air conditioning application generally unsuitable from an economic standpoint.
It can be readily seen from the foregoing that it would be desirable to provide a double-walled air conditioning equipment cabinet structure which eliminates, or at least substantially reduces, the above-mentioned problems, limitations and disadvantages heretofore associated with conventionally configurated cabinetry of both single and double-walled construction. It is accordingly an object of the present invention to provide such a cabinet structure.